In a Time-Division Duplex (TDD) communication system, a single frequency is assigned to a communication node for both transmission and reception purposes. In TDD communication systems, a data stream is divided into frames and each frame is further divided into time slots. Within each frame a different time slot is assigned for transmission and reception purposes. However, the, frequency spectrum is a valuable resource which is divided into non-overlapping spectrum bands and further assigned to different communication nodes. Typically, one or more frequency bands (e.g. spectrum bands) being used by one or more communication nodes are re-used by other distant communication nodes to increase both the coverage and capacity of the communication system. The phenomenon of frequency reuse can result in crosstalk between two different communication nodes using the same frequency. This crosstalk from two different communication nodes using the same frequency is known as co-channel interference. Apart from the co-channel interference, a communication node also experiences interference from other communication nodes that operate on a nearby or adjacent frequency. Interference resulting from other communication nodes that are adjacent in frequency to the communication node is known as adjacent channel interference. Thus, whenever a communication node transmits its data, there is a significant potential for interference due to data transmitted by co-channel or adjacent channel communication nodes. This interference forces can constrain the communication node to transmit at lower data rates consistent with lower signal to interference-noise ratio.
Thus, there exists a need for a scheduling method that schedules the transmission from communication nodes in such a way that the interference between the transmissions from communication nodes is reduced.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.